【摘要】 采用回火焊道工艺在低合金钢SA508-3钢管上堆焊镍基合金制备试验件,利用该试验件研究不同堆焊层对应的热影响区组织形貌。结果显示,首层堆焊使SA508-3钢热影响区形成淬火马氏体,但该类组织在随后的堆焊层焊接热过程中会发生回火转变,并随着焊层的增加,转变效应累积,最终完全纠正热影响区的淬火不良组织。试件两端焊趾附近区域因高温回火累积时间不足造成的回火不充分,使得首层堆焊在热影响区产生内马氏体以及由于热影响区内残余奥氏体分解产生的马氏体等不良组织未得到完全纠正,可通过特定工艺的补充焊接予以消除。更多还原

【Abstract】 The surfacing is conducted on nickel-base alloy 690 layers on the low alloy steel(SA508-3) by using the temper bead technology to prepare the specimens. The microstructures of the heat-affected zones(HAZ) corresponding to the different layers of specimen are researched. The results show that the martensitic transformation of HAZ is found after the first layer surfacing by using welding technology in this paper. The martensite temper transformation occurs in the welding thermal process of follow-up surfacing layers,and the transformation effect accumulates as the layer increases,finally the bad quenching microstructure of HAZ is corrected completely. Because of insufficient temper caused by insufficient cumulative time of high-temperature temper in the area near by the toe of weld at the both ends of the specimen,the martensite produced in HAZ by the first layer surfacing and the martensite generated by the decomposition of residual austenite in HAZ are corrected incompletely,but this problem can be resolved by the additional welding with specific technology.更多还原